Des was an Old Belvederian and played on the first two of the famous seven-in-a-row Leinster Senior Cup winning sides. He was first capped for Ireland in Paris in 1948 and went on to win the Triple Crown and Grand Slam. He played in all of Ireland's games from 1948 to 1952.
IRFU President Andy Crawford led the tributes to the former Old Belvedere number eight: "The IRFU would like to pass on its deepest sympathies to Des O'Brien's family at his recent passing. Des served both Ireland and his club with great distinction and he will be sorely missed by his past team-mates and his friends.
He continued, "His name will remain one synonymous with the 1948 Grand Slam, but his services to the game went beyond his first international season, where he went on to captain Ireland and manage the British & Irish Lions. May he rest in peace."